/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell (papowell@astart.com)
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 */

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 *
 * More Recently:
 *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
 *  This was ugly.  It is still ugly.  I opted out of floating point
 *  numbers, but the formatter understands just about everything
 *  from the normal C string format, at least as far as I can tell from
 *  the Solaris 2.5 printf(3S) man page.
 *
 *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
 *    Ok, added some minimal floating point support, which means this
 *    probably requires libm on most operating systems.  Don't yet
 *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
 *    was pretty badly broken, it just wasn't being exercised in ways
 *    which showed it, so that's been fixed.  Also, formated the code
 *    to mutt conventions, and removed dead code left over from the
 *    original.  Also, there is now a builtin-test, just compile with:
 *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
 *    and run snprintf for results.
 *
 *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats.
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
 *    The original code assumed that both snprintf() and vsnprintf() were
 *    missing.  Some systems only have snprintf() but not vsnprintf(), so
 *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
 *
 *  Andrew Tridgell (tridge@samba.org) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 * tridge@samba.org, idra@samba.org, April 2001
 *    got rid of fcvt code (twas buggy and made testing harder)
 *    added C99 semantics
 *
 **************************************************************/

#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <stdarg.h>
#include <stdlib.h>

#define NO_CONFIG_H 1
#define HAVE_STRING_H 1
#define HAVE_CTYPE_H 1
#define HAVE_STDLIB_H 1

#define HAVE_SNPRINTF 1
#define HAVE_VSNPRINTF 1
#define HAVE_C99_VSNPRINTF 1

#define HAVE_LONG_DOUBLE 1
#define HAVE_LONG_LONG 1
#define HAVE_SNPRINTF 1
#define HAVE_C99_VSNPRINTF 1
#define HAVE_ASPRINTF 1
#define HAVE_VASPRINTF 1

#ifndef NO_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif
#include <sys/types.h>
#include <stdarg.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#if defined(HAVE_SNPRINTF) && defined(HAVE_VSNPRINTF) &&                       \
    defined(HAVE_C99_VSNPRINTF)
/* only include stdio.h if we are not re-defining snprintf or vsnprintf */
#include <stdio.h>
/* make the compiler happy with an empty file */
void dummy_snprintf(void) {}
#else

#ifdef HAVE_LONG_DOUBLE
#define LDOUBLE long double
#else
#define LDOUBLE double
#endif

#ifdef HAVE_LONG_LONG
#define LLONG long long
#else
#define LLONG long
#endif

static size_t dopr(char *buffer, size_t maxlen, const char *format,
                   va_list args);
static void fmtstr(char *buffer, size_t *currlen, size_t maxlen, char *value,
                   int flags, int min, int max);
static void fmtint(char *buffer, size_t *currlen, size_t maxlen, long value,
                   int base, int min, int max, int flags);
static void fmtfp(char *buffer, size_t *currlen, size_t maxlen, LDOUBLE fvalue,
                  int min, int max, int flags);
static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS 1
#define DP_S_MIN 2
#define DP_S_DOT 3
#define DP_S_MAX 4
#define DP_S_MOD 5
#define DP_S_CONV 6
#define DP_S_DONE 7

/* format flags - Bits */
#define DP_F_MINUS (1 << 0)
#define DP_F_PLUS (1 << 1)
#define DP_F_SPACE (1 << 2)
#define DP_F_NUM (1 << 3)
#define DP_F_ZERO (1 << 4)
#define DP_F_UP (1 << 5)
#define DP_F_UNSIGNED (1 << 6)

/* Conversion Flags */
#define DP_C_SHORT 1
#define DP_C_LONG 2
#define DP_C_LDOUBLE 3
#define DP_C_LLONG 4

#define char_to_int(p) ((p) - '0')
#ifndef MAX
#define MAX(p, q) (((p) >= (q)) ? (p) : (q))
#endif

static size_t dopr(char *buffer, size_t maxlen, const char *format,
                   va_list args) {
    char ch;
    LLONG value;
    LDOUBLE fvalue;
    char *strvalue;
    int min;
    int max;
    int state;
    int flags;
    int cflags;
    size_t currlen;

    state = DP_S_DEFAULT;
    currlen = flags = cflags = min = 0;
    max = -1;
    ch = *format++;

    while (state != DP_S_DONE) {
        if (ch == '\0')
            state = DP_S_DONE;

        switch (state) {
        case DP_S_DEFAULT:
            if (ch == '%')
                state = DP_S_FLAGS;
            else
                dopr_outch(buffer, &currlen, maxlen, ch);
            ch = *format++;
            break;
        case DP_S_FLAGS:
            switch (ch) {
            case '-':
                flags |= DP_F_MINUS;
                ch = *format++;
                break;
            case '+':
                flags |= DP_F_PLUS;
                ch = *format++;
                break;
            case ' ':
                flags |= DP_F_SPACE;
                ch = *format++;
                break;
            case '#':
                flags |= DP_F_NUM;
                ch = *format++;
                break;
            case '0':
                flags |= DP_F_ZERO;
                ch = *format++;
                break;
            default:
                state = DP_S_MIN;
                break;
            }
            break;
        case DP_S_MIN:
            if (isdigit((unsigned char)ch)) {
                min = 10 * min + char_to_int(ch);
                ch = *format++;
            } else if (ch == '*') {
                min = va_arg(args, int);
                ch = *format++;
                state = DP_S_DOT;
            } else {
                state = DP_S_DOT;
            }
            break;
        case DP_S_DOT:
            if (ch == '.') {
                state = DP_S_MAX;
                ch = *format++;
            } else {
                state = DP_S_MOD;
            }
            break;
        case DP_S_MAX:
            if (isdigit((unsigned char)ch)) {
                if (max < 0)
                    max = 0;
                max = 10 * max + char_to_int(ch);
                ch = *format++;
            } else if (ch == '*') {
                max = va_arg(args, int);
                ch = *format++;
                state = DP_S_MOD;
            } else {
                state = DP_S_MOD;
            }
            break;
        case DP_S_MOD:
            switch (ch) {
            case 'h':
                cflags = DP_C_SHORT;
                ch = *format++;
                break;
            case 'l':
                cflags = DP_C_LONG;
                ch = *format++;
                if (ch == 'l') { /* It's a long long */
                    cflags = DP_C_LLONG;
                    ch = *format++;
                }
                break;
            case 'L':
                cflags = DP_C_LDOUBLE;
                ch = *format++;
                break;
            default:
                break;
            }
            state = DP_S_CONV;
            break;
        case DP_S_CONV:
            switch (ch) {
            case 'd':
            case 'i':
                if (cflags == DP_C_SHORT)
                    value = va_arg(args, int);
                else if (cflags == DP_C_LONG)
                    value = va_arg(args, long int);
                else if (cflags == DP_C_LLONG)
                    value = va_arg(args, LLONG);
                else
                    value = va_arg(args, int);
                fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
                break;
            case 'o':
                flags |= DP_F_UNSIGNED;
                if (cflags == DP_C_SHORT)
                    value = va_arg(args, unsigned int);
                else if (cflags == DP_C_LONG)
                    value = (long)va_arg(args, unsigned long int);
                else if (cflags == DP_C_LLONG)
                    value = (long)va_arg(args, unsigned LLONG);
                else
                    value = (long)va_arg(args, unsigned int);
                fmtint(buffer, &currlen, maxlen, value, 8, min, max, flags);
                break;
            case 'u':
                flags |= DP_F_UNSIGNED;
                if (cflags == DP_C_SHORT)
                    value = va_arg(args, unsigned int);
                else if (cflags == DP_C_LONG)
                    value = (long)va_arg(args, unsigned long int);
                else if (cflags == DP_C_LLONG)
                    value = (LLONG)va_arg(args, unsigned LLONG);
                else
                    value = (long)va_arg(args, unsigned int);
                fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
                break;
            case 'X':
                flags |= DP_F_UP;
            case 'x':
                flags |= DP_F_UNSIGNED;
                if (cflags == DP_C_SHORT)
                    value = va_arg(args, unsigned int);
                else if (cflags == DP_C_LONG)
                    value = (long)va_arg(args, unsigned long int);
                else if (cflags == DP_C_LLONG)
                    value = (LLONG)va_arg(args, unsigned LLONG);
                else
                    value = (long)va_arg(args, unsigned int);
                fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags);
                break;
            case 'f':
                if (cflags == DP_C_LDOUBLE)
                    fvalue = va_arg(args, LDOUBLE);
                else
                    fvalue = va_arg(args, double);
                /* um, floating point? */
                fmtfp(buffer, &currlen, maxlen, fvalue, min, max, flags);
                break;
            case 'E':
                flags |= DP_F_UP;
            case 'e':
                if (cflags == DP_C_LDOUBLE)
                    fvalue = va_arg(args, LDOUBLE);
                else
                    fvalue = va_arg(args, double);
                break;
            case 'G':
                flags |= DP_F_UP;
            case 'g':
                if (cflags == DP_C_LDOUBLE)
                    fvalue = va_arg(args, LDOUBLE);
                else
                    fvalue = va_arg(args, double);
                break;
            case 'c':
                dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
                break;
            case 's':
                strvalue = va_arg(args, char *);
                if (max == -1) {
                    max = strlen(strvalue);
                }
                if (min > 0 && max >= 0 && min > max)
                    max = min;
                fmtstr(buffer, &currlen, maxlen, strvalue, flags, min, max);
                break;
            case 'p':
                strvalue = va_arg(args, void *);
                fmtint(buffer, &currlen, maxlen, (long)strvalue, 16, min, max,
                       flags);
                break;
            case 'n':
                if (cflags == DP_C_SHORT) {
                    short int *num;
                    num = va_arg(args, short int *);
                    *num = currlen;
                } else if (cflags == DP_C_LONG) {
                    long int *num;
                    num = va_arg(args, long int *);
                    *num = (long int)currlen;
                } else if (cflags == DP_C_LLONG) {
                    LLONG *num;
                    num = va_arg(args, LLONG *);
                    *num = (LLONG)currlen;
                } else {
                    int *num;
                    num = va_arg(args, int *);
                    *num = currlen;
                }
                break;
            case '%':
                dopr_outch(buffer, &currlen, maxlen, ch);
                break;
            case 'w':
                /* not supported yet, treat as next char */
                ch = *format++;
                break;
            default:
                /* Unknown, skip */
                break;
            }
            ch = *format++;
            state = DP_S_DEFAULT;
            flags = cflags = min = 0;
            max = -1;
            break;
        case DP_S_DONE:
            break;
        default:
            /* hmm? */
            break; /* some picky compilers need this */
        }
    }
    if (maxlen != 0) {
        if (currlen < maxlen - 1)
            buffer[currlen] = '\0';
        else if (maxlen > 0)
            buffer[maxlen - 1] = '\0';
    }

    return currlen;
}

static void fmtstr(char *buffer, size_t *currlen, size_t maxlen, char *value,
                   int flags, int min, int max) {
    int padlen, strln; /* amount to pad */
    int cnt = 0;

#ifdef DEBUG_SNPRINTF
    printf("fmtstr min=%d max=%d s=[%s]\n", min, max, value);
#endif
    if (value == 0) {
        value = "<NULL>";
    }

    for (strln = 0; value[strln]; ++strln)
        ; /* strlen */
    padlen = min - strln;
    if (padlen < 0)
        padlen = 0;
    if (flags & DP_F_MINUS)
        padlen = -padlen; /* Left Justify */

    while ((padlen > 0) && (cnt < max)) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        --padlen;
        ++cnt;
    }
    while (*value && (cnt < max)) {
        dopr_outch(buffer, currlen, maxlen, *value++);
        ++cnt;
    }
    while ((padlen < 0) && (cnt < max)) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        ++padlen;
        ++cnt;
    }
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static void fmtint(char *buffer, size_t *currlen, size_t maxlen, long value,
                   int base, int min, int max, int flags) {
    int signvalue = 0;
    unsigned long uvalue;
    char convert[20];
    int place = 0;
    int spadlen = 0; /* amount to space pad */
    int zpadlen = 0; /* amount to zero pad */
    int caps = 0;

    if (max < 0)
        max = 0;

    uvalue = value;

    if (!(flags & DP_F_UNSIGNED)) {
        if (value < 0) {
            signvalue = '-';
            uvalue = -value;
        } else {
            if (flags & DP_F_PLUS) /* Do a sign (+/i) */
                signvalue = '+';
            else if (flags & DP_F_SPACE)
                signvalue = ' ';
        }
    }

    if (flags & DP_F_UP)
        caps = 1; /* Should characters be upper case? */

    do {
        convert[place++] = (caps ? "0123456789ABCDEF"
                                 : "0123456789abcdef")[uvalue % (unsigned)base];
        uvalue = (uvalue / (unsigned)base);
    } while (uvalue && (place < 20));
    if (place == 20)
        place--;
    convert[place] = 0;

    zpadlen = max - place;
    spadlen = min - MAX(max, place) - (signvalue ? 1 : 0);
    if (zpadlen < 0)
        zpadlen = 0;
    if (spadlen < 0)
        spadlen = 0;
    if (flags & DP_F_ZERO) {
        zpadlen = MAX(zpadlen, spadlen);
        spadlen = 0;
    }
    if (flags & DP_F_MINUS)
        spadlen = -spadlen; /* Left Justifty */

#ifdef DEBUG_SNPRINTF
    printf("zpad: %d, spad: %d, min: %d, max: %d, place: %d\n", zpadlen,
           spadlen, min, max, place);
#endif

    /* Spaces */
    while (spadlen > 0) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        --spadlen;
    }

    /* Sign */
    if (signvalue)
        dopr_outch(buffer, currlen, maxlen, signvalue);

    /* Zeros */
    if (zpadlen > 0) {
        while (zpadlen > 0) {
            dopr_outch(buffer, currlen, maxlen, '0');
            --zpadlen;
        }
    }

    /* Digits */
    while (place > 0)
        dopr_outch(buffer, currlen, maxlen, convert[--place]);

    /* Left Justified spaces */
    while (spadlen < 0) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        ++spadlen;
    }
}

static LDOUBLE abs_val(LDOUBLE value) {
    LDOUBLE result = value;

    if (value < 0)
        result = -value;

    return result;
}

static LDOUBLE POW10(int exp) {
    LDOUBLE result = 1;

    while (exp) {
        result *= 10;
        exp--;
    }

    return result;
}

static LLONG ROUND(LDOUBLE value) {
    LLONG intpart;

    intpart = (LLONG)value;
    value = value - intpart;
    if (value >= 0.5)
        intpart++;

    return intpart;
}

/* a replacement for modf that doesn't need the math library. Should
 be portable, but slow */
static double my_modf(double x0, double *iptr) {
    int i;
    long l;
    double x = x0;
    double f = 1.0;

    for (i = 0; i < 100; i++) {
        l = (long)x;
        if (l <= (x + 1) && l >= (x - 1))
            break;
        x *= 0.1;
        f *= 10.0;
    }

    if (i == 100) {
        /* yikes! the number is beyond what we can handle. What do we do? */
        (*iptr) = 0;
        return 0;
    }

    if (i != 0) {
        double i2;
        double ret;

        ret = my_modf(x0 - l * f, &i2);
        (*iptr) = l * f + i2;
        return ret;
    }

    (*iptr) = l;
    return x - (*iptr);
}

static void fmtfp(char *buffer, size_t *currlen, size_t maxlen, LDOUBLE fvalue,
                  int min, int max, int flags) {
    int signvalue = 0;
    double ufvalue;
    char iconvert[311];
    char fconvert[311];
    int iplace = 0;
    int fplace = 0;
    int padlen = 0; /* amount to pad */
    int zpadlen = 0;
    int caps = 0;
    int index;
    double intpart;
    double fracpart;
    double temp;

    /*
     * AIX manpage says the default is 0, but Solaris says the default
     * is 6, and sprintf on AIX defaults to 6
     */
    if (max < 0)
        max = 6;

    ufvalue = abs_val(fvalue);

    if (fvalue < 0) {
        signvalue = '-';
    } else {
        if (flags & DP_F_PLUS) { /* Do a sign (+/i) */
            signvalue = '+';
        } else {
            if (flags & DP_F_SPACE)
                signvalue = ' ';
        }
    }

#if 0
	if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
#endif

#if 0
	if (max == 0) ufvalue += 0.5; /* if max = 0 we must round */
#endif

    /*
     * Sorry, we only support 16 digits past the decimal because of our
     * conversion method
     */
    if (max > 16)
        max = 16;

    /* We "cheat" by converting the fractional part to integer by
     * multiplying by a factor of 10
     */

    temp = ufvalue;
    my_modf(temp, &intpart);

    fracpart = ROUND((POW10(max)) * (ufvalue - intpart));

    if (fracpart >= POW10(max)) {
        intpart++;
        fracpart -= POW10(max);
    }

    /* Convert integer part */
    do {
        temp = intpart;
        my_modf(intpart * 0.1, &intpart);
        temp = temp * 0.1;
        index = (int)((temp - intpart + 0.05) * 10.0);
        /* index = (int) (((double)(temp*0.1) -intpart +0.05) *10.0); */
        /* printf ("%llf, %f, %x\n", temp, intpart, index); */
        iconvert[iplace++] =
            (caps ? "0123456789ABCDEF" : "0123456789abcdef")[index];
    } while (intpart && (iplace < 311));
    if (iplace == 311)
        iplace--;
    iconvert[iplace] = 0;

    /* Convert fractional part */
    if (fracpart) {
        do {
            temp = fracpart;
            my_modf(fracpart * 0.1, &fracpart);
            temp = temp * 0.1;
            index = (int)((temp - fracpart + 0.05) * 10.0);
            /* index = (int) ((((temp/10) -fracpart) +0.05) *10); */
            /* printf ("%lf, %lf, %ld\n", temp, fracpart, index); */
            fconvert[fplace++] =
                (caps ? "0123456789ABCDEF" : "0123456789abcdef")[index];
        } while (fracpart && (fplace < 311));
        if (fplace == 311)
            fplace--;
    }
    fconvert[fplace] = 0;

    /* -1 for decimal point, another -1 if we are printing a sign */
    padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
    zpadlen = max - fplace;
    if (zpadlen < 0)
        zpadlen = 0;
    if (padlen < 0)
        padlen = 0;
    if (flags & DP_F_MINUS)
        padlen = -padlen; /* Left Justifty */

    if ((flags & DP_F_ZERO) && (padlen > 0)) {
        if (signvalue) {
            dopr_outch(buffer, currlen, maxlen, signvalue);
            --padlen;
            signvalue = 0;
        }
        while (padlen > 0) {
            dopr_outch(buffer, currlen, maxlen, '0');
            --padlen;
        }
    }
    while (padlen > 0) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        --padlen;
    }
    if (signvalue)
        dopr_outch(buffer, currlen, maxlen, signvalue);

    while (iplace > 0)
        dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]);

#ifdef DEBUG_SNPRINTF
    printf("fmtfp: fplace=%d zpadlen=%d\n", fplace, zpadlen);
#endif

    /*
     * Decimal point.  This should probably use locale to find the correct
     * char to print out.
     */
    if (max > 0) {
        dopr_outch(buffer, currlen, maxlen, '.');

        while (fplace > 0)
            dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]);
    }

    while (zpadlen > 0) {
        dopr_outch(buffer, currlen, maxlen, '0');
        --zpadlen;
    }

    while (padlen < 0) {
        dopr_outch(buffer, currlen, maxlen, ' ');
        ++padlen;
    }
}

static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c) {
    if (*currlen < maxlen) {
        buffer[(*currlen)] = c;
    }
    (*currlen)++;
}

#if !defined(HAVE_VSNPRINTF) || !defined(HAVE_C99_VSNPRINTF)
int vsnprintf(char *str, size_t count, const char *fmt, va_list args) {
    return dopr(str, count, fmt, args);
}
#endif

#if !defined(HAVE_SNPRINTF) || !defined(HAVE_C99_VSNPRINTF)
int snprintf(char *str, size_t count, const char *fmt, ...) {
    size_t ret;
    va_list ap;

    va_start(ap, fmt);
    ret = vsnprintf(str, count, fmt, ap);
    va_end(ap);
    return ret;
}
#endif

#endif

#ifndef HAVE_VASPRINTF
int vasprintf(char **ptr, const char *format, va_list ap) {
    int ret;

    ret = vsnprintf(NULL, 0, format, ap);
    if (ret <= 0)
        return ret;

    (*ptr) = (char *)io_calloc(1, ret + 1);
    if (!*ptr)
        return -1;
    ret = vsnprintf(*ptr, ret + 1, format, ap);

    return ret;
}
#endif

#ifndef HAVE_ASPRINTF
int asprintf(char **ptr, const char *format, ...) {
    va_list ap;
    int ret;

    va_start(ap, format);
    ret = vasprintf(ptr, format, ap);
    va_end(ap);

    return ret;
}
#endif

#ifdef TEST_SNPRINTF

int sprintf(char *str, const char *fmt, ...);

int main(void) {
    char buf1[1024];
    char buf2[1024];
    char *fp_fmt[] = {"%1.1f",  "%-1.5f",  "%1.5f",   "%123.9f",
                      "%10.5f", "% 10.5f", "%+22.9f", "%+4.9f",
                      "%01.3f", "%4f",     "%3.1f",   "%3.2f",
                      "%.0f",   "%f",      "-16.16f", NULL};
    double fp_nums[] = {6442452944.1234, -1.5,   134.21, 91340.2,
                        341.1234,        0203.9, 0.96,   0.996,
                        0.9996,          1.996,  4.136,  0};
    char *int_fmt[] = {"%-1.5d", "%1.5d",   "%123.9d",  "%5.5d",
                       "%10.5d", "% 10.5d", "%+22.33d", "%01.3d",
                       "%4d",    "%d",      NULL};
    long int_nums[] = {-1, 134, 91340, 341, 0203, 0};
    char *str_fmt[] = {"10.5s", "5.10s", "10.1s", "0.10s", "10.0s", "1.10s",
                       "%s",    "%.1s",  "%.10s", "%10s",  NULL};
    char *str_vals[] = {"hello", "a", "", "a longer string", NULL};
    int x, y;
    int fail = 0;
    int num = 0;

    printf("Testing snprintf format codes against system sprintf...\n");

    for (x = 0; fp_fmt[x]; x++) {
        for (y = 0; fp_nums[y] != 0; y++) {
            int l1 = snprintf(NULL, 0, fp_fmt[x], fp_nums[y]);
            int l2 = snprintf(buf1, sizeof(buf1), fp_fmt[x], fp_nums[y]);
            sprintf(buf2, fp_fmt[x], fp_nums[y]);
            if (strcmp(buf1, buf2)) {
                printf("snprintf doesn't match Format: %s\n\tsnprintf = "
                       "[%s]\n\t sprintf = [%s]\n",
                       fp_fmt[x], buf1, buf2);
                fail++;
            }
            if (l1 != l2) {
                printf("snprintf l1 != l2 (%d %d) %s\n", l1, l2, fp_fmt[x]);
                fail++;
            }
            num++;
        }
    }

    for (x = 0; int_fmt[x]; x++) {
        for (y = 0; int_nums[y] != 0; y++) {
            int l1 = snprintf(NULL, 0, int_fmt[x], int_nums[y]);
            int l2 = snprintf(buf1, sizeof(buf1), int_fmt[x], int_nums[y]);
            sprintf(buf2, int_fmt[x], int_nums[y]);
            if (strcmp(buf1, buf2)) {
                printf("snprintf doesn't match Format: %s\n\tsnprintf = "
                       "[%s]\n\t sprintf = [%s]\n",
                       int_fmt[x], buf1, buf2);
                fail++;
            }
            if (l1 != l2) {
                printf("snprintf l1 != l2 (%d %d) %s\n", l1, l2, int_fmt[x]);
                fail++;
            }
            num++;
        }
    }

    for (x = 0; str_fmt[x]; x++) {
        for (y = 0; str_vals[y] != 0; y++) {
            int l1 = snprintf(NULL, 0, str_fmt[x], str_vals[y]);
            int l2 = snprintf(buf1, sizeof(buf1), str_fmt[x], str_vals[y]);
            sprintf(buf2, str_fmt[x], str_vals[y]);
            if (strcmp(buf1, buf2)) {
                printf("snprintf doesn't match Format: %s\n\tsnprintf = "
                       "[%s]\n\t sprintf = [%s]\n",
                       str_fmt[x], buf1, buf2);
                fail++;
            }
            if (l1 != l2) {
                printf("snprintf l1 != l2 (%d %d) %s\n", l1, l2, str_fmt[x]);
                fail++;
            }
            num++;
        }
    }

    printf("%d tests failed out of %d.\n", fail, num);

    printf("seeing how many digits we support\n");
    {
        double v0 = 0.12345678901234567890123456789012345678901;
        for (x = 0; x < 100; x++) {
            snprintf(buf1, sizeof(buf1), "%1.1f", v0 * pow(10, x));
            sprintf(buf2, "%1.1f", v0 * pow(10, x));
            if (strcmp(buf1, buf2)) {
                printf("we seem to support %d digits\n", x - 1);
                break;
            }
        }
    }

    return 0;
}
#endif /* SNPRINTF_TEST */
